Pontiac firebird 1968 - Road Test

7E-60
1968 PONTIAC SERVICE MANUAL
MANUAL LINKAGE
Manual linkage adjustment and the associated neu-
tral safety switch are Important from a safety
standpoint. The neutral safety switch should be
adjusted so that the engine will start in the Park
and Neutral positions only.
With the selector lever in the Park position, the
parking pawl should freely engage and prevent the
vehicle from rolling. The pointer on the indicator
quadrant should line up properly with the range
indicators in all ranges.
ROAD TEST
(ATTACH PRESSURE GAUGE TO TRANSMISSION)
The car owner should accompany the tester and
the complaint analyzed under the same or simulated
conditions.
SHIFT PATTERN CHECK
Check all the shifts in the following manner:
Drive Range:
Position selector lever in Drive Range, accelerat-
ing the vehicle from 0 mph. A 1-2 and 2-3 shift
should occur at all throttle openings. The shift
points will vary with the throttle opening. As the
vehicle decreases in speed to 0 mph, the 3-2 and
2-1 shifts should occur.
Super Range:
Position the selector lever in Super Range and
accelerate the vehicle from 0 mph. A 1-2 shift
should occur at all throttle openings. No 2-3 shift
can be obtained in this range. The 1-2 shift point
will vary with throttle opening. As the vehicle de-
creases in speed to 0 mph, a 2-1 shift should occur.
Lo Range:
Position the selector lever in Lo Range. No up-
shift should occur in this range, regardless of
throttle opening.
2nd Gear Overrun Braking:
Position the selector lever in the Drive Range and,
with the car speed at approximately 35 mph, move
the selector lever to Super Range. The transmission
should downshift to 2nd. An increase in engine rpm
and an engine braking effect should be noticed. Line
pressure should change from 60 psi to approximately
150 psi in 2nd.
1st Gear - Downhill or Overrun Braking:
With the selector lever in Super at approximately
30 mph at constant throttle, reposition the selector
lever into Lo Range. An increase in engine rpm and
a braking effect should be noticed. Line pressure
should be approximately 150 psi (Figs. 171 and 172).
TURBO HYDRA-MATIC TRANSMISSION-OIL PRESSURE CHECK
I. Oil Pressure Check - Road or Normal Operating Conditions
While road testing with the transmission oil pressure gauge attached and the vacuum
modulator tube connected, the transmission pressures should check approximately as
shown in Fig. 7E-171.
Super Range
Minimum Maximum
2nd Gear -
Steady road load at approximately
25 mph
145 psi
155 psi
Gear
Selector Lever Position
Minimum Maximum
1st
Drive \
2nd
("Zero" throttle to full I
60
150
3rd
throttle) j
3rd
Drive Range, Zero Throttle
60
at 30 mph
Reverse Rev. (Zero to full throttle)
95
260
Fig. 7E-171 Oil Pressure Check - Road or Normal Operating Conditions
II. Oil Pressure Check - With Car Stationary and Engine at 1200 rpm
With the transmission oil pressure gauge attached and the vacuum modulator tube
disconnected, the transmission pressures should check approximately as shown in
Fig. 7E-172.